The various embodiments described herein generally relate to elevator installations. More particularly, the various embodiments described herein relate to a system and method for coupling a suspension medium to a load carrying structure of an elevator installation.
In one example of a known elevator installation, a suspension medium—such as a rope or flat belt-type rope—interconnects a counterweight and a cabin. A drive motor causes the suspension medium to move in order to thereby move the counterweight and the cabin up and down along a hoistway. The suspension medium loops around at least one sheave system, which may be mounted to the cabin or the counterweight, or both. The sheave system is, for example, mounted a frame of the cabin.
U.S. Pat. No. 7,665,580 discloses several sheave systems arranged next to each other on the counterweight or the cabin. Each sheave system has a U-shaped carrier in which a deflecting roller and a ball socket are positioned. The deflecting roller is mounted between the legs of the U-shaped carrier, and the ball socket exists in a curve that connects the two legs. A flat belt-type suspension medium loops around the deflecting roller. A tie bolt is part of the ball socket and extends from the carrier towards a support structure of the counterweight or cabin. The tie bolt is fixed in a through hole of the support structure. Further, each sheave system is individually rotatable and adjustable about an axis parallel to a take-off direction of a respective suspension medium.
Even though such sheave systems have a variety of advantages, for example, because they are individually rotatable, these sheave systems may not be suitable for certain applications. For example, if an elevator installation is subject to modernization and the existing cabin frame and counterweight are to be retained without any modification, it may not be possible to provide the frame with, for example, the required through holes for the tie bolts, or to adjust the sheave system for varying hoistway layouts. There is, therefore, a need for an alternative technology for coupling a suspension medium to a cabin or counterweight that overcomes these limitations.